Self lubricating spherical bearing assembly

ABSTRACT

A spherical bearing assembly having an inner race member and an outer race member, the inner surface of the outer race member being a concave spherical surface, the outer surface of the inner member being a complimentary convex spherical surface, the inner member including a spool member having two annular lips at each end thereof, and at least three spherical segments interlocked by the annular lips in an axial direction on the spool member, a gap provided between at least two of the spherical segments, an intermediate spherical segment interposed between the two segments in the area defined by the gap.

United States Patent 1 1 McCloskey I SELF LUBRICATING SPHERICAL BEARING ASSEMBLY [75] Inventor: Albert R. McCloskey. Fairficld,

Conn.

[73] Assignee: Rockwell International Corporation,

Pittsburgh, Pa.

[22] Filed: Jan. 10, 1974 [2]] Appl. No.: 432,l45

[52] U.S. Cl 308/72; 308/238 [51] Int. CL... Fl6c 23/04; Fl6c 27/02; Fl6c 33/20 [58] Field of Search 29/1484, 149.5, 308/72, 308/238 [56] References Cited UNITED STATES PATENTS 2,675,283 4/1954 Thompson 308/238 3,089,22l 5/1963 Barr l. 29/1484 McCloskey 29/1495 Ahcl 308/72 Primary Examiner-Robert 5. Ward, .Ir. Assistant Examiner-Howard Beltran [57] ABSTRACT A spherical bearing assembly having an inner race member and an outer race member, the inner surface of the outer race member being a concave spherical surface, the outer surface of the inner member being a complimentary convex spherical surface, the inner member including a spool member having two annular lips at each end thereof, and at least three spherical segments interlocked by the annular lips in an axial direction on the spool member, a gap provided between at least two of the spherical segments, an inter mediate spherical segment interposed between the two segments in the area defined by the gap 8 Claims, 13 Drawing Figures PATENTEDJUH 7 0 ms SHEET Q2 liIlIllu A SELF LUBRICATING SPHERKAL BEARING ASSEMBLY BACKGROUND OF THE INVENTION The present invention relates generally to selfaligning bearings having a ball-like inner member with a convex outer surface and an outer member having an inner surface with a complimentary concave spherical inner face. These types of bearings. which are commonly called spherical bearings," have been utilized in industry for a substantial period of time. The technological evolution of these type bearings has been directed more in the terms of material composition of its various component parts rather than toward basic changes in design concepts. Accordingly. the design advances in spherical bearings have not been substantial in nature and thereby presently limiting their applications.

One area in which the spherical bearings have been extensively applied is the aircraft industry. This is due to the spherical bearing selflaligning characteristic. A typical such spplication is marrying ofa spherical bearing to a landing gear strut or member of an airplane. In this application the outer race is commonly press-fitted into a housing or the like rendering it difficult to remove and/or maintain. When any such maintenance is required, such as replacing of the ball. the entire bearing assembly including the inner and outer race member would have to be removed and replaced by an entirely new bearing assembly. Such an operation could entail substantial expense and down time of the entire aircraft.

There are a number of prior art type spherical bearings which have been addressed to this kind of problem. One such type prior art bearing is the messer- Schmidt" bearing. A concept of this bearing is that the ball can be removed in the field without disassembling the entire bearing, that is, removing the outer race member from its mounting. The messerschmidt type spherical bearing has proved somewhat unsatisfactory in that its overall bearing surface is decreased by the provision of a slot. This decrease or rather limited bearing surface area has a marked negative effect on the bearing performance characteristics.

SUMMARY OF THE INVENTION It is therefore, a primary object of the present invention to provide a spherical bearing assembly having an inner race member and an outer race member, the inner surface of the outer race member being a concave spherical surface, the outer surface of the inner member being a complimentary convex spherical surface, said inner member including a spool member having two annular lips at each end thereof, and at least three spherical segments interlocked by the annular lips in an axial direction with said spool member. a gap provided between at least two of said spherical segments, an intermediate self-lubricating spherical segment interposed between the two segments in the area defined by the gap.

It is yet another object of the present invention to provide a spherical bearing assembly which has a rotational redundancy. That is. the inner member is adapted to be rotatably mounted within the outer member. A first bearing surface between these two members being defined by the convex outer surface of the inner member and the complimentary concave inner surface of the outer member. The rotational redundancy provided by the spherical bearing of the present invention is the second bearing surface between the longitudinal inner surface of the segments of the inner member and the cylindrical outer surface of the spool member.

It is still another object of the present invention to provide a spherical bearing assembly in accordance with the present invention wherein the spool member is provided with annular lips. one lip disposed at each end of the spool member.

It is still another object of the present invention to provide a spherical bearing assembly in accordance with the present invention wherein the annular lips of the spool member have an outer surface which is a continuation of the convex spherical surface of the inner member.

It is yet another object of the present invention to provide a spherical bearing assembly in accordance with the present invention wherein the annular lips on the spool member maintain the segments upon the spool member so as to mechanically interlock them thereon when the member is in its operational position.

It is still another object of the present invention to provide a spherical bearing assembly in which the intermediate segments are smaller in circumferential dimension than the spherical bearing segments.

It is still another object of the present invention to provide a spherical bearing assembly in which the intermediate spherical segment is manufactured from a selflubricating plastic such as Teflon," a trademark of the DuPont Corporation.

It is yet another object of the present invention to provide a spherical bearing assembly in which the intermediate spherical segment is manufactured from a felt material which absorbs and carrys oil for lubricating and dispersing oil on the bearing surfaces.

It is yet another object of the present invention to provide a spherical bearing assembly in which the intermediate spherical segment is biased by a biasing means to maintain its contact with the bearing surfaces. The biasing action may be accomplished by sandwiching a resilient material 32 within the intermediate spherical segment in a preloaded fashion so as to exert a force on the two parts 34 and 36 of the segment 30. This is best illustrated in FIG. 11.

Embodiments of the bearing according to the concept of the present invention are shown and/or described by way of example in the accompanying drawings and following description of the invention without attempting to show or describe all of the various forms and modifications in which the invention might be embodied; the invention being measured by the appended claims and not by the details of the specification.

FIG. 1 is a side elevational view of the spherical bearing assembly embodying the present invention with the longitudinal axis of the outer race member and the inner race member being substantially coincident;

FIG. 2 is a side elevational view of the spherical bearing assembly embodying the present invention with the longitudinal axis of the inner race member and the outer race member being substantially perpendicular, that is, the inner race member has been rotated substantially in one plane;

FIG. 3 is a front elevational view of the spherical bearing assembly of FIG. 1'.

FIG. 4 is a front sectional view taken along line 44 of FIG. 1;

llG. 5 is a front elevational view of the bearing of FIG. 2.

FIG. 6 is a front sectional vie\\ taken along line 66 of FIG. 2'.

FIG. 7 is a perspective view ofthc inner race member alone in an assembled condition;

FIGS. 8a. 8b, 8( illustrate a perspective view of the component parts of the inner race member of FIG. 7;

FIG. 9 is a perspective sectional view of the spherical bearing of FIG. I; and

FIG. 10 is a perspective sectional view ofthc bearing of FIG. 2 with one ofthe segments and one of the intermediate spherical segments of the inner race member removed.

FIG. II is a sectional view of a form of intermediate spherical segment in accordance with the present invention.

DESCRIPTION OF THE INVENTION A spherical bearing embodying the concept of the present invention is generally indicated, as appropriate. by numeral 10 on the attached drawing as set forth in FIGS. 1 through 10, inclusive The bearing 10 has been shown as a spherical hearing, however. the present invention is also directly ap plicable to male or female rod end type bearings and the like.

The spherical bearing 10 comprises an outer member 12 which may be provided with an outer cylindrical surface 14. The outer member 10 may also be provided with two annular faces 16. The outer member 12 is further provided with a concave spherical inner surface 18. It may be noted at this juncture that the outer member 12 may be similar to the outer race members as found in the prior art.

The basic thrust of the present invention is to be found in the inner race member. hereafter referred to as the inner member which is typically formed, in the prior art. as a single solid member. The inner member as distinguished from the inner members of the prior art is a composite member having several parts. One component part or member is the spool member 22. The spool member 22 may be characterized as a cylin drically shaped spool having two annular lips 24, one at each end thereof. The spool member 22 and the annular lips 24. are so sized as to be able to be placed within the surface defined by the concave inner surface 18 of the outer member 12. This can be best seen in FIGS. 2. 5, 6 and 10.

The spool member 22 and its various associated parts may be rotated such that its longitudinal axis is perpendicular to the longitudinal axis of the outer race member 12. When the spool member is rotated in such a fashion that the convex outer surface ofthe inner member 20 is exposed substantially all ofthe convex surface of the inner member which is formed and defined by at least three segments 26. There may be at least three equally sized segments 26 on the spool member 22 well as three intermediate spherical members 30. The annular lips 24 maintain the positional integrity. in an axial direction. of the segments 26 and intermediate spherical members 30 on the spool member 22. Hovvever. the segments 26 intermediate spherical members 30 may be removed from the spool member 22 when the spool member is rotated in the above noted fashion. Each segment 26 and intermediate spherical segments 30 may be moved in turn from the spool member 22 ultimately leaving the spool member completely devoid of the segments 26 and intermediate segments 30. Thereafter. the spool member can be removed entirely from the outer member 12. It can be seen. therefore. that the inner member can be completely dismantled and removed from the outer member 12 without dislodging or otherwise interferring with the position or the condition of the outer member with respect to its mounting surface (not shown). Therefor the outer face member is fixedly attached to some structural surface such as by press-fit or the like. For example. in an aircraft type application. a new inner member may be in sertcd quickly and efficiently without disturbing any other part of the aircraft except that part which is dircctly attached to the inner member 20.

A very important feature of the present invention is that the intermediate spherical segments. which are interposed in gaps between the segments 26 provide for continuous lubrication of the various bearing surfaces such as the outer convex surfaces of segments 26 and the inner concave surface 18 of the outer member 12. The intermediate spherical segments 30 may be of a oil absorbing and carrying felt material or of a suitable self-lubricating plastic material such as polytetrafluoroethylenc. In the latter case it may be solely of Teflon such as a Teflon block. or could be suitably biased by a biasing means such as a spring (not shown) to transfer a plastic film to the bearing surfaces such as the con cave inner surface 18 of the outer member 12. The spherical bearing 10 inherently embodies a second or redundant bearing surface. In particular. the inner sur faces 28 of the segments 26 and intermediate segments 30 and the outer surface 3 (FIG. 8a) of the spool member 22 may define a second bearing surface. This bearing surface can become particularly important in a situation where there may be interference between the inner member and the outer member at the bearing surface defined by the concave inner surface of the outer member 12 and the convex outer surface of the inner member 20. Upon any such interference, which may be caused by corrosion. dirt or the like. the above noted second bearing surface between the spherical segments 26 and 30 and spool member 22 could then provide for a degree of movement. This movement can be further enhanced by the selflubricating action of the intermediate spherical segments 30 which would lubricate the second bearing surface.

The annular lips 24 may be so shaped such that their outer surface would be a continuation of the spherical surface of the segments. Additionally, the outer surface of the annular lips may be defined by a number of other forms such as a chordal section subtending the spherical surface defined by the outer surface of the segments 26 and 30. Additionally. the annular lips may be re duced in size to a point where they merely maintain the axial position of the segments 26 on the spool member 22 but are not involved in any way with the bearing surface area of the segments 26 and 30.

As before mentioned, the present invention provides a marked improvement in the ability to service spherical hearings in the field without displacing or otherwise dislodging the outer race member. This is accomplished without any compromise in the bearing per formance or characteristic such as a reduction in the overall bearing surface which is typified by the prior art bearings such the messerschmidt type ball spherical bearing.

From the above description of the invention along with various figures set forth in the drawings it will be readily seen and appreciated that a spherical bearing embodying the concept of the present imention ill positively and effectively accomplish the objectives of the invention. The above-noted embodiment is shown by way of example without attempting to show all the various forms and modifications in which the invention might be embodied; the invention being measured by the appended claims and not the specific details of the specification.

I claim:

1. A spherical bearing assembly having an inner race member and an outer race member. the inner surface of the outer race member being a concave spherical surface, the outer surface of the inner member being a complimentary convex spherical surface. the inner member including a spool member having two annular lips at each end thereof and at least three axially segmented spherical segments interlocked by said annular lips in an axial direction on the spool member, a gap provided between at least two of said spherical segments, a self-lubricating segment interposed between said two segments in the area defined said gap.

2. A spherical bearing assembly in accordance with claim 1 wherein said intermediate segments are smaller in circumferential dimension than said spherical bearing segments 3. A spherical bearing assembly in accordance with claim 1 wherein said intermediate segments are manufactured from a self-lubricating plastic.

4. A spherical bearing assembly in accordance with claim 3 wherein said self-lubricating plastic is polytetrafluoroethylene.

5. A spherical bearing assembly in accordance with claim 4 wherein said intermediate segment is completely of polytetrafluoroethylene.

6. A spherical bearing assembly in accordance with claim 4 wherein said intermediate segment is a laminar structure having a intermediate liner of resilient material for biasing the polytetrafluoroethylene against the bearing surfaces of the spherical bearing assembly.

7. A spherical bearing assembly in accordance with claim 1 wherein said intermediate segment is a felt material capable of absorbing. carrying and disposing a lubricating oil film on the bearing surfaces of the spheri cal bearing assembly 8. A spherical bearing assembly in accordance with claim 1 wherein said intermediate segments are spherical segments having an outer surface generally conforming to the convex spherical surface of said inner 

1. A spherical bearing assembly having an inner race member and an outer race member, the inner surface of the outer race member being a concave spherical surface, the outer surface of the inner member being a complimentary convex spherical surface, the inner member including a spool member having two annular lips at each end thereof and at least three axially segmented spherical segments interlocked by said annular lips in an axial direction on the spool member, a gap provided between at least two of said spherical segments, a self-lubricating segment interposed between said two segments in the area defined said gap.
 2. A spherical bearing assembly in accordance with claim 1 wherein said intermediate segments are smaller in circumferential dimension than said spherical bearing segments.
 3. A spherical bearing assembly in accordance with claim 1 wherein said intermediate segments are manufactured from a self-lubricating plastic.
 4. A spherical bearing assemBly in accordance with claim 3 wherein said self-lubricating plastic is polytetrafluoroethylene.
 5. A spherical bearing assembly in accordance with claim 4 wherein said intermediate segment is completely of polytetrafluoroethylene.
 6. A spherical bearing assembly in accordance with claim 4 wherein said intermediate segment is a laminar structure having a intermediate liner of resilient material for biasing the polytetrafluoroethylene against the bearing surfaces of the spherical bearing assembly.
 7. A spherical bearing assembly in accordance with claim 1 wherein said intermediate segment is a felt material capable of absorbing, carrying and disposing a lubricating oil film on the bearing surfaces of the spherical bearing assembly.
 8. A spherical bearing assembly in accordance with claim 1 wherein said intermediate segments are spherical segments having an outer surface generally conforming to the convex spherical surface of said inner member. 